A recent study found that four bad behaviors—smoking, drinking too much alcohol, not exercising, and not eating enough fruits and veggies—can hustle you into an early grave, and, in effect, age you by as many as 12 years.

Fortunately, you can do something to correct these and other unhealthy behaviors. Adopt the following nine habits to keep your body looking and feeling young.

Making just a few changes in your lifestyle can help you live longer.

DON’T OVEREAT

If you want to live to 100, leaving a little bit of food on your plate may be a good idea. Author Dan Buettner, who studies longevity around the world, found that the oldest Japanese people stop eating when they are feeling only about 80% full.

St. Louis University researchers have confirmed that eating less helps you age slower; in a 2008 study they found that limiting calories lowered production of T3, a thyroid hormone that slows metabolism—and speeds up the aging process.

STAYOUTOFTHESUN

Avoiding too much sun can head off skin cancer, and it can also keep you looking young by preventing wrinkles, fine lines, and saggy skin.

It’s never too early—or too late—to add sunscreen to your daily skin-care regimen (look for an SPF of 30 or higher). And don’t focus only on your face. Sun damage spots and splotches on your chest and neck will also make you appear older.

DRINKINMODERATION

Women who have two or more drinks a day and men who have three or more may run into detrimental effects ranging from weight gain to relationship problems. But in smaller quantities, alcohol can actually be good for you.

A 2010 study in the Journal of the American College of Cardiology linked light drinking (defined as one drink a day for women and two for men) to significant heart benefits.EATFRUITSANDVEGETABLES

Getting fewer than three servings of fruits and vegetables a day can eat away at your health. Nutritional powerhouses filled with fiber and vitamins, fruits and veggies can lower your risk of heart disease by 76% and may even play a role in decreasing your risk of breast cancer.

As an added bonus, the inflammation-fighting and circulation-boosting powers of the antioxidants in fruits and veggies can banish wrinkles.FOCUSONFITNESS

Daily exercise may be the closest thing we have to a fountain of youth. A 2008 study found that regular high-intensity exercise (such as running) can add up to four years to your life, which isn’t surprising given the positive effects working out has on your heart, mind, and metabolism.

Quitting smoking is perhaps the single most important thing you can do for your health—and your life span. A study published in the American Journal of Public Health found that women who quit smoking by age 35 add roughly six to eight years to their lives.

It’s never too late to kick the habit. Quitting can slow disease and increase survival odds even in smokers who have already caused significant damage to their lungs, like those with early lung cancer or COPD.GETBUSY

Having satisfying sex two to three times per week can add as many as three years to your life. Getting busy can burn an impressive amount of calories—sometimes as much as running for 30 minutes. (Which would you rather do?)

Too much time in front of the boob tube can take a serious toll on your health. In fact, a 2010 study found that people who watched four or more hours a day were 46% more likely to die from any cause than people who watched less than two hours a day.

Even cutting back a little can help; each additional hour you watch increases your overall risk of dying by 11% and dying from heart disease by 18%.REACHOUT

Research shows that you’re at greater risk of heart disease without a strong network of friends and family. Loneliness can cause inflammation, and in otherwise healthy people it can be just as dangerous as having high cholesterol or even smoking.

Loneliness seems to pose the greatest risk for elderly people, who are also prone to depression.